1. Field of the Invention
The present invention relates to an apparatus for enabling electronic musical instruments to carry out automatic play in synchronism with the playback of data such as audio data, graphics data recorded on a compact disc (CD) or the like.
2. Description of the Prior Art
It is known that, if a recording medium recorded in a so-called minus-one system (i.e., system in which a piano concerto is recorded except for the part of piano) is reproduced by operating a compact disc player, an analog disc player, a digital audio tape recorder or the like and if the player plays an musical instrument in the background of reproduced sound of this audio data, then a rich reality can be obtained and also the playing timing can be understood, which is very useful in musical training for beginners.
In order to reproduce the above-mentioned playing state by using automatic play, audio data is initially reproduced from the recording medium. Then, the player carries out the musical play by using an electronic musical instrument in synchronism with the reproduced sound of audio data in actual practice. At that time, musical play data is recorded in a sequencer in a real time fashion. After the above-mentioned operation and processing, the audio data is reproduced from the recording medium in synchronism with the playback of the automatic play by the sequencer.
However, the above-mentioned system in which automatic playing data is input in a real time fashion is difficult for the beginner. That is, the beginner cannot control the musical play speed to coincide with the playback speed of the audio data reproduced in the background.
To remove this disadvantage, the audio playback speed is decreased by adjusting the driving state of the recording medium by the user. If the user sets the speed (tempo) suitable for the musical play and inputs the automatic playing data in a real time fashion, then the problem of the speed (tempo) can be solved.
This method, however, cannot solve the following problems.
That is, if the playback speed of the audio data is changed, then the interval (pitch) of the reproduced sound of audio data also is changed accordingly. To remove this problem, a circuit for manually returning the interval of the audio reproduced sound to the original one must be additionally provided or the tuning of the musical sound pitch of the electronic musical instrument must be carried out one more time in unison with the interval of the reproduced sound of the audio data, which is very complex.
Further, if the synchronizing playback is carried out after the user recorded the automatic playing data in the sequencer, then the user must remember the audio playback speed adjusted in the recording mode and the adjusted value in the tuning of the electronic musical instrument. In other words, unless upon playback the user sets again the system setting data such as the audio playback speed and the adjusted value in the tuning of the electronic musical instrument to the same state as those in the recording timing point, then the playback speed of the recording medium and the playback tempo of the automatic play and the interval of the audio reproduced sound and the interval of the reproduced sound of the automatic play do not coincide with each other, whereby the audio playback and the automatic play are disharmonized.
This is also true for the case when the automatic play is carried out in synchronism with the playback of an image. For example, if a landscape and a score are displayed as image data and automatic playing data is recorded in synchronism with the display of the displayed image, then the playback speed of the image and the playback tempo of the automatic play must be synchronized with each other during the playback of the automatic playing data, otherwise the automatic play and the display of the score will not become coincident with each other.